[PATCH] nfsd4: fix open_downgrade

Bad bookkeeping of the share reservations when handling open upgrades was
causing open downgrade to fail.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 7167dcf..82c36cc 100644 (file)
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1609,26 +1609,26 @@ nfs4_upgrade_open(struct svc_rqst *rqstp, struct svc_fh *cur_fh, struct nfs4_sta
 {
        struct file *filp = stp->st_vfs_file;
        struct inode *inode = filp->f_dentry->d_inode;
-       unsigned int share_access;
+       unsigned int share_access, new_writer;
        int status;
 
        set_access(&share_access, stp->st_access_bmap);
-       share_access = ~share_access;
-       share_access &= open->op_share_access;
-
-       if (!(share_access & NFS4_SHARE_ACCESS_WRITE))
-               return nfsd4_truncate(rqstp, cur_fh, open);
+       new_writer = (~share_access) & open->op_share_access
+                       & NFS4_SHARE_ACCESS_WRITE;
 
-       status = get_write_access(inode);
-       if (status)
-               return nfserrno(status);
+       if (new_writer) {
+               status = get_write_access(inode);
+               if (status)
+                       return nfserrno(status);
+       }
        status = nfsd4_truncate(rqstp, cur_fh, open);
        if (status) {
-               put_write_access(inode);
+               if (new_writer)
+                       put_write_access(inode);
                return status;
        }
        /* remember the open */
-       filp->f_mode = (filp->f_mode | FMODE_WRITE) & ~FMODE_READ;
+       filp->f_mode |= open->op_share_access;
        set_bit(open->op_share_access, &stp->st_access_bmap);
        set_bit(open->op_share_deny, &stp->st_deny_bmap);